Heretofore there has existed the problem of applying lettering of uniform height to a sheet of paper and wherein the line of lettering extends at right angles to an edge thereof and wherein successive lines of lettering are uniformly spaced from and parallel to the first line of lettering. Lettering in a straight line has heretofore been achieved to a limited extent by lettering along a straight edge of another object. The use of such a lettering device or the use of a slotted lettering device applied to a sheet nevertheless does not accurately determine that the line of lettering extends at right angles to the edge of the paper sheet and that successive lines will all be parallel thereto, and uniformly spaced.